Liquid Silicone Transfer Injection Molding - Compression Molding Machine

Liquid Silicone Transfer Injection Molding is not real LSR injection molding, but a simplified liquid silicone injection molding, which is also considered as converted advanced compression molding. Production of liquid silicone transfer molding is by compression molding machine, not by LSR injection machine. In general, compression molding machine only can produce the solid silicone rubber products (HCR). However, with a additional LSR raw material feeding system and LSR transfer injection molding, compression molding machine can also produce liquid silicone product.  

Liquid Silicone Transfer Molding is similar to LSR injection molding, with a cold runner system. Liquid Silicone compound A and compound B are placed in the additional feeding system. This system transfer liquid silicone automatically to the runner in mold clamping plate. And then piston needle valve inject liquid silicone to the lower plate runner or directly to mold cavitives. Runners are around each mold cavity, from which LSR flows to each mold cavity. When specific liquid silicone are injected to the mold cavities. The piston needld valve is retracted. Raw material stops getting into the runner and mold cavity.

Liquid Silicone Injection Molding - LSR Injection Molding Machine

Liquid Silicone Injection Molding is also known as LSR injection mold or LIM, with a complex mold structure. In contrast to liquid silicone transfer molding, mold cavities are in a mold core. Once the more core run out, we only need to replace with a new mold core to the plate. This mold core is embeded in the lower plate. But in liquid silicone injection mold, cavities are directly carved in lower plate, without any mold core. Besides the cooling system (cold runner system), silicone injection molding also includes a ejector system. LSR inejction molding need LSR inejction molding machine for production.

Characteristics of Liquid Silicone Transfer Injection Molding

Liquid Silicone Transfer Molding is very cost effective. As transfer mold structure is not complicate as LSR injection molding, as well as the cooling system can be shared to different LSR products, transfer molding cost is cheaper than LSR injection molding. At the development stage, if R&D team don't have sufficient budget, silicone transfer molding is a good choice.

Unit cost can be lower to some extent through LSR transfer molding. Compression molding machine can accommodate a large mold plate compared to liquid silicone injection molding machine. There are more cavities (chamber) in transfer molding plate, which help increase the production efficiency and decrease the unit price.

Accuracy of product by liquid silicone transfer molding is not good as products by liquid silicone injection molding. Liquid silicone transfer injection molding is suitable for product with simple geometries and no high precision requirements. Transfer molding structure like the location pins, and accuracy of plates clamping, compression machine's clamping force all these elements will affect liquid product accuracy.  Transfer molding clamping mainly depend on the locations pins and compression machine force. If your product with strict tolerence, like ±0.05mm, LSR injection molding can meet the strict tolerence requirement.

As for complicate geometries products or thick-wall products, liquid silicone injection molding is better than LSR transfer molding. LSR inejction molding can keep a vaccum environment during product vulcanization, while transfer molding can not. Vacuum environment can ensure liquid silicone completely flow to every corner of cavity. And complex product will not have defects like unfilled hole, or not fully cured part. 

Liquid Silicone Transfer Molded production are with stable quality and better consistency. Specific amount of raw material are trnasfered to the molding and flow evenly to each cavity. So the product dimensions can be accurate and stable. 

Conclusion

From the advancement perspective, LSR Injection Molding > Liquid Silicone Transfer Molding > Compression Molding

From the mold cost perspective, LSR Injection Molding > Liquid Silicone Transfer Molding > Compression Molding

From the accuracy perspective, LIM>LSR Trransfer Molding > Compression Molding

We should tell the differences between liquid silicone transfer inejction molding and LSR injection molding. Some people may confuse why the mold quote has a big difference in different manufacturers. That is because some quote you the LSR transfer molding, while some quote liquid silicone injection molding. You can choose a better one accoridng to your needs.